Several authors4-15 describe the deposition and
application of AuSn thin film solder. Aschenbrenner et
al.6 describes a process where the chip pad is metallized
with gold and the substrate is coated with tin. The eutectic
reaction takes place during the die bonding process. z-
phase can be observed on both sides of the joint.
Disadvantage is that layers of brittle intermetallic phases
might be formed and that Kirkendall voids can appear